Down syndrome children generate fewer appropriate social signals and exhibit less responsiveness to their mothers' signals than do non-delayed children. Research suggests that in the absence of these potent elicitors of maternal response, many mothers of Down syndrome children adopt a controlling and directive interactive style. The proposed study seeks to determine whether this directiveness occurs at the expense of responsiveness thereby interfering with the development of Down syndrome children's interactive social skills. This proposal examines maternal responsiveness to children's social signals in mothers of Down syndrome children. As part of an ongoing project, videotapes have been collected of 50 Down syndrome and 50 mental age matched non-delayed children and their mothers when the children were between 10 and 29 months mental age. From this sample, Down syndrome children with a 10 to 17 month mental age (n=28) and their mental age matched non-delayed cohorts are being assessed longitudinally at two subsequent points. For the proposed study, behavioral microanalysis will be used to characterize attentional, vocal, and affective responsiveness in mothers of Down syndrome as compared with mothers of non-delayed children. The extent to which the developmental appropriateness of early maternal interactions influences the children's later performance and interactive behavior will then be examined. In addition, the effects of children's mental development, social responsiveness, and family SES on maternal responsiveness over time will also be examined. Using this longitudinal design, we will be able to evaluate whether differences between mothers of Down syndrome and non-delayed children represent adaptive behaviors that facilitate or maladaptive behaviors that inhibit a healthy social interchange.